FFmpeg: libavformat/mmf.c Source File

00001 /*
00002  * Yamaha SMAF format
00003  * Copyright (c) 2005 Vidar Madsen
00004  *
00005  * This file is part of FFmpeg.
00006  *
00007  * FFmpeg is free software; you can redistribute it and/or
00008  * modify it under the terms of the GNU Lesser General Public
00009  * License as published by the Free Software Foundation; either
00010  * version 2.1 of the License, or (at your option) any later version.
00011  *
00012  * FFmpeg is distributed in the hope that it will be useful,
00013  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00014  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00015  * Lesser General Public License for more details.
00016  *
00017  * You should have received a copy of the GNU Lesser General Public
00018  * License along with FFmpeg; if not, write to the Free Software
00019  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00020  */
00021 #include "avformat.h"
00022 #include "internal.h"
00023 #include "avio_internal.h"
00024 #include "pcm.h"
00025 #include "riff.h"
00026 
00027 typedef struct {
00028     int64_t atrpos, atsqpos, awapos;
00029     int64_t data_size;
00030 } MMFContext;
00031 
00032 static const int mmf_rates[] = { 4000, 8000, 11025, 22050, 44100 };
00033 
00034 static int mmf_rate(int code)
00035 {
00036     if((code < 0) || (code > 4))
00037         return -1;
00038     return mmf_rates[code];
00039 }
00040 
00041 #if CONFIG_MMF_MUXER
00042 static int mmf_rate_code(int rate)
00043 {
00044     int i;
00045     for(i = 0; i < 5; i++)
00046         if(mmf_rates[i] == rate)
00047             return i;
00048     return -1;
00049 }
00050 
00051 /* Copy of end_tag() from avienc.c, but for big-endian chunk size */
00052 static void end_tag_be(AVIOContext *pb, int64_t start)
00053 {
00054     int64_t pos;
00055 
00056     pos = avio_tell(pb);
00057     avio_seek(pb, start - 4, SEEK_SET);
00058     avio_wb32(pb, (uint32_t)(pos - start));
00059     avio_seek(pb, pos, SEEK_SET);
00060 }
00061 
00062 static int mmf_write_header(AVFormatContext *s)
00063 {
00064     MMFContext *mmf = s->priv_data;
00065     AVIOContext *pb = s->pb;
00066     int64_t pos;
00067     int rate;
00068 
00069     rate = mmf_rate_code(s->streams[0]->codec->sample_rate);
00070     if(rate < 0) {
00071         av_log(s, AV_LOG_ERROR, "Unsupported sample rate %d\n", s->streams[0]->codec->sample_rate);
00072         return -1;
00073     }
00074 
00075     ffio_wfourcc(pb, "MMMD");
00076     avio_wb32(pb, 0);
00077     pos = ff_start_tag(pb, "CNTI");
00078     avio_w8(pb, 0); /* class */
00079     avio_w8(pb, 0); /* type */
00080     avio_w8(pb, 0); /* code type */
00081     avio_w8(pb, 0); /* status */
00082     avio_w8(pb, 0); /* counts */
00083     avio_write(pb, "VN:libavcodec,", sizeof("VN:libavcodec,") -1); /* metadata ("ST:songtitle,VN:version,...") */
00084     end_tag_be(pb, pos);
00085 
00086     avio_write(pb, "ATR\x00", 4);
00087     avio_wb32(pb, 0);
00088     mmf->atrpos = avio_tell(pb);
00089     avio_w8(pb, 0); /* format type */
00090     avio_w8(pb, 0); /* sequence type */
00091     avio_w8(pb, (0 << 7) | (1 << 4) | rate); /* (channel << 7) | (format << 4) | rate */
00092     avio_w8(pb, 0); /* wave base bit */
00093     avio_w8(pb, 2); /* time base d */
00094     avio_w8(pb, 2); /* time base g */
00095 
00096     ffio_wfourcc(pb, "Atsq");
00097     avio_wb32(pb, 16);
00098     mmf->atsqpos = avio_tell(pb);
00099     /* Will be filled on close */
00100     avio_write(pb, "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00", 16);
00101 
00102     mmf->awapos = ff_start_tag(pb, "Awa\x01");
00103 
00104     avpriv_set_pts_info(s->streams[0], 64, 1, s->streams[0]->codec->sample_rate);
00105 
00106     avio_flush(pb);
00107 
00108     return 0;
00109 }
00110 
00111 static int mmf_write_packet(AVFormatContext *s, AVPacket *pkt)
00112 {
00113     AVIOContext *pb = s->pb;
00114     avio_write(pb, pkt->data, pkt->size);
00115     return 0;
00116 }
00117 
00118 /* Write a variable-length symbol */
00119 static void put_varlength(AVIOContext *pb, int val)
00120 {
00121     if(val < 128)
00122         avio_w8(pb, val);
00123     else {
00124         val -= 128;
00125         avio_w8(pb, 0x80 | val >> 7);
00126         avio_w8(pb, 0x7f & val);
00127     }
00128 }
00129 
00130 static int mmf_write_trailer(AVFormatContext *s)
00131 {
00132     AVIOContext *pb = s->pb;
00133     MMFContext *mmf = s->priv_data;
00134     int64_t pos, size;
00135     int gatetime;
00136 
00137     if (s->pb->seekable) {
00138         /* Fill in length fields */
00139         end_tag_be(pb, mmf->awapos);
00140         end_tag_be(pb, mmf->atrpos);
00141         end_tag_be(pb, 8);
00142 
00143         pos = avio_tell(pb);
00144         size = pos - mmf->awapos;
00145 
00146         /* Fill Atsq chunk */
00147         avio_seek(pb, mmf->atsqpos, SEEK_SET);
00148 
00149         /* "play wav" */
00150         avio_w8(pb, 0); /* start time */
00151         avio_w8(pb, 1); /* (channel << 6) | wavenum */
00152         gatetime = size * 500 / s->streams[0]->codec->sample_rate;
00153         put_varlength(pb, gatetime); /* duration */
00154 
00155         /* "nop" */
00156         put_varlength(pb, gatetime); /* start time */
00157         avio_write(pb, "\xff\x00", 2); /* nop */
00158 
00159         /* "end of sequence" */
00160         avio_write(pb, "\x00\x00\x00\x00", 4);
00161 
00162         avio_seek(pb, pos, SEEK_SET);
00163 
00164         avio_flush(pb);
00165     }
00166     return 0;
00167 }
00168 #endif /* CONFIG_MMF_MUXER */
00169 
00170 static int mmf_probe(AVProbeData *p)
00171 {
00172     /* check file header */
00173     if (p->buf[0] == 'M' && p->buf[1] == 'M' &&
00174         p->buf[2] == 'M' && p->buf[3] == 'D' &&
00175         p->buf[8] == 'C' && p->buf[9] == 'N' &&
00176         p->buf[10] == 'T' && p->buf[11] == 'I')
00177         return AVPROBE_SCORE_MAX;
00178     else
00179         return 0;
00180 }
00181 
00182 /* mmf input */
00183 static int mmf_read_header(AVFormatContext *s,
00184                            AVFormatParameters *ap)
00185 {
00186     MMFContext *mmf = s->priv_data;
00187     unsigned int tag;
00188     AVIOContext *pb = s->pb;
00189     AVStream *st;
00190     int64_t size;
00191     int rate, params;
00192 
00193     tag = avio_rl32(pb);
00194     if (tag != MKTAG('M', 'M', 'M', 'D'))
00195         return -1;
00196     avio_skip(pb, 4); /* file_size */
00197 
00198     /* Skip some unused chunks that may or may not be present */
00199     for(;; avio_skip(pb, size)) {
00200         tag = avio_rl32(pb);
00201         size = avio_rb32(pb);
00202         if(tag == MKTAG('C','N','T','I')) continue;
00203         if(tag == MKTAG('O','P','D','A')) continue;
00204         break;
00205     }
00206 
00207     /* Tag = "ATRx", where "x" = track number */
00208     if ((tag & 0xffffff) == MKTAG('M', 'T', 'R', 0)) {
00209         av_log(s, AV_LOG_ERROR, "MIDI like format found, unsupported\n");
00210         return -1;
00211     }
00212     if ((tag & 0xffffff) != MKTAG('A', 'T', 'R', 0)) {
00213         av_log(s, AV_LOG_ERROR, "Unsupported SMAF chunk %08x\n", tag);
00214         return -1;
00215     }
00216 
00217     avio_r8(pb); /* format type */
00218     avio_r8(pb); /* sequence type */
00219     params = avio_r8(pb); /* (channel << 7) | (format << 4) | rate */
00220     rate = mmf_rate(params & 0x0f);
00221     if(rate  < 0) {
00222         av_log(s, AV_LOG_ERROR, "Invalid sample rate\n");
00223         return -1;
00224     }
00225     avio_r8(pb); /* wave base bit */
00226     avio_r8(pb); /* time base d */
00227     avio_r8(pb); /* time base g */
00228 
00229     /* Skip some unused chunks that may or may not be present */
00230     for(;; avio_skip(pb, size)) {
00231         tag = avio_rl32(pb);
00232         size = avio_rb32(pb);
00233         if(tag == MKTAG('A','t','s','q')) continue;
00234         if(tag == MKTAG('A','s','p','I')) continue;
00235         break;
00236     }
00237 
00238     /* Make sure it's followed by an Awa chunk, aka wave data */
00239     if ((tag & 0xffffff) != MKTAG('A', 'w', 'a', 0)) {
00240         av_log(s, AV_LOG_ERROR, "Unexpected SMAF chunk %08x\n", tag);
00241         return -1;
00242     }
00243     mmf->data_size = size;
00244 
00245     st = avformat_new_stream(s, NULL);
00246     if (!st)
00247         return AVERROR(ENOMEM);
00248 
00249     st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
00250     st->codec->codec_id = CODEC_ID_ADPCM_YAMAHA;
00251     st->codec->sample_rate = rate;
00252     st->codec->channels = 1;
00253     st->codec->bits_per_coded_sample = 4;
00254     st->codec->bit_rate = st->codec->sample_rate * st->codec->bits_per_coded_sample;
00255 
00256     avpriv_set_pts_info(st, 64, 1, st->codec->sample_rate);
00257 
00258     return 0;
00259 }
00260 
00261 #define MAX_SIZE 4096
00262 
00263 static int mmf_read_packet(AVFormatContext *s,
00264                            AVPacket *pkt)
00265 {
00266     MMFContext *mmf = s->priv_data;
00267     int ret, size;
00268 
00269     if (url_feof(s->pb))
00270         return AVERROR(EIO);
00271 
00272     size = MAX_SIZE;
00273     if(size > mmf->data_size)
00274         size = mmf->data_size;
00275 
00276     if(!size)
00277         return AVERROR(EIO);
00278 
00279     if (av_new_packet(pkt, size))
00280         return AVERROR(EIO);
00281     pkt->stream_index = 0;
00282 
00283     ret = avio_read(s->pb, pkt->data, pkt->size);
00284     if (ret < 0)
00285         av_free_packet(pkt);
00286 
00287     mmf->data_size -= ret;
00288 
00289     pkt->size = ret;
00290     return ret;
00291 }
00292 
00293 #if CONFIG_MMF_DEMUXER
00294 AVInputFormat ff_mmf_demuxer = {
00295     .name           = "mmf",
00296     .long_name      = NULL_IF_CONFIG_SMALL("Yamaha SMAF"),
00297     .priv_data_size = sizeof(MMFContext),
00298     .read_probe     = mmf_probe,
00299     .read_header    = mmf_read_header,
00300     .read_packet    = mmf_read_packet,
00301     .read_seek      = pcm_read_seek,
00302 };
00303 #endif
00304 #if CONFIG_MMF_MUXER
00305 AVOutputFormat ff_mmf_muxer = {
00306     .name              = "mmf",
00307     .long_name         = NULL_IF_CONFIG_SMALL("Yamaha SMAF"),
00308     .mime_type         = "application/vnd.smaf",
00309     .extensions        = "mmf",
00310     .priv_data_size    = sizeof(MMFContext),
00311     .audio_codec       = CODEC_ID_ADPCM_YAMAHA,
00312     .video_codec       = CODEC_ID_NONE,
00313     .write_header      = mmf_write_header,
00314     .write_packet      = mmf_write_packet,
00315     .write_trailer     = mmf_write_trailer,
00316 };
00317 #endif